1. Technical Field
The present invention relates to a robot, a gear device, and a manufacturing method for the gear device.
2. Related Art
In a robot including a robot arm including at least one arm, for example, a joint section of the robot arm is driven by a motor. In general, a driving force from the motor is reduced by a reduction gear, which is a type of a gear device.
For example, a reduction gear according to JP-A-3-179094 (Patent Literature 1) is configured from a circular spline (a rigid internal gear), a flex spline (a flexible external gear), and a wave generator. When the wave generator is rotated, the flex spline sequentially moves a meshing position with the circular spline while being elastically deformed. Since the wave generator has a smaller number of teeth than the circular spline, the circular spline rotates in a direction opposite to a rotating direction of the wave generator according to the rotation of the wave generator because of the difference in the number of teeth.
In the reduction gear according to Patent Literature 1, the circular spline and the flex spline mesh with each other with an extremely small backlash. The flex spline and the wave generator frictionally slide with a high load. When characteristics of lubricant used in a meshing section of the circular spline and the flex spline and a frictional sliding section of the flex spline and the wave generator are insufficient and the reduction gear is used in a robot, there has been a problem in that seizure, wear, and the like easily occur relatively early.